Knock-Knock Door Chime
Here is a cool system. A knock on the door rings a remote door bell! I was thinking about doing something similar some time ago. My idea was to do it in reverse though, when someone rings the doorbell I would make a solenoid knock on the door. I think this would provide some entertainment for the delivery people. 🙂 “No Doorbell? No Problem! Knock-Knock Door Chime automatically alerts you